I follow the Git mailing list, and he's even-keeled and surprisingly helpful in discussions. The tone of the original post is representative of what he normally writes.

I'm sure he's no saint, but his most famous rants were responses to sniping. The Minix/Linux debate was started by Tanenbaum, Bram Cohen picked a fight over merge strategies in a list discussion, and the 'C++ sucks' rant was in response to some flamebait.